This study aimed to analyze the applicability of the Union for International Cancer Control (UICC) tumor-node-metastasis (TNM) classification 8th edition for Chinese patients with gastric cancer.A review of all inpatient and outpatient records of patients with gastric cancer was conducted in the First Affiliated Hospital of China Medical University and Liaoning Cancer Hospital and Institute. All patients who met the inclusion criteria and were seen from January 1980 through December 2009 were included in the study. The primary outcome was 5-year survival, which was analyzed according to the decade of diagnosis and TNM classifications.Two thousand five hundred fifty-four patients were enrolled in this study. When classified according to the UICC TNM classification of gastric cancer 8th edition, the prognoses of patients with stage IIIB (n = 250) and stage IIIC (n = 101) disease were not significantly different (P = .332). However, if T4aN2 patients were classified as having stage IIIB disease, and T4bN2 and T4aN3a patients were classified as having stage IIIC disease, the prognoses of stage IIIB (n = 221) and stage IIIC (n = 172) patients were significantly different (P = .03).Classifying T4bN0 patients as having stage IIIB disease, and T4bN2 and T4aN3a patients as having stage IIIC disease according to the 8th edition of UICC gastric cancer TNM classifications better stratified Chinese patients and predicted prognoses.